Overseas conservation
Paignton zoo is involved in the conservation and research projects on rhinos, duikersa and cheetah in Zimbabwe, over four years. In Nigeria, its involved in environmental education and conservation since 1993.the Omo Forest reserve is one of the few tropical forest left in Nigeria .research have conformed that African forest elephants ,chimpanzees and white-throated guenon monkeys live in Omo forest, all of which are endangered. Money is raised by elephant keeper talks at the zoo and is used to employ two environmental educators and a ranger.
Second (major) biological aspect: captive breeding
Captive Breeding: Black rhino
Modern zoos apply captive breeding programmes to help save endangered species from Savannah to the humble dormouse here in England. Paignton zoo is proud of its recent successful birth of a black rhino calf by breeding after a gestation of 15-16 months.
(Picture right is the baby rhino,
(.org.uk))
Rhinoceros number has been fallen by 98% in the last 200 years.The main threat of rhinos are paoching and habitat loss.Rhino hones have been used to make ornamental handles of daggers in Yeman.Rhinos horns and toenails are used in traditional chineese medicaines.
In Africa, the place once rhino once lived has been cleared for human farming and homes .in Asia, forest dwelling are threatened by logging.
Though rhino are facing extinction, zoos like Paignton are showing efforts in conservation over past 30years.in 1998 black rhinos were presumed extinct in Zambia .in 2003 they were reintroduced and now there are at least 20.this project aims on build on this founding project. (Information taken from walls of Paignton zoo).
Captive Breeding: The Technical side
There are many techniques which can be applied to species which are not naturally inclined to breed in captivity, or who are later unable to rear their offspring. Some of these methods can be used to breed from animals on opposite sides of the globe.
Artificial Incubation - Used a lot with aquatic animals and some birds which experience very high death rates during the hatchling period. Eggs are collected and incubated under artificial conditions, then reared to beyond the critical size before release.
(See picture right – From www.falcons.co.uk)
Artificial Insemination - Sperm can be collected from donor males, processed, and frozen for long-term storage and for worldwide distribution to artificially inseminate females. A common method is to put the male near a “teaser” female who is giving off the pheromones which indicate she is in heat, keep her out of reach, but near enough to attract the attention of the male, who when unable to reach the female is likely to mount a replacement “fake” female allowing the keeper to collect the sperm.
Embryo Transfer “surrogacy” (in mammals) – There is only a certain number of offspring a single female can have during her lifetime even though she has thousands of egg follicles in her ovaries. The solution is simple . . . the female is super ovulated (the release of multiple eggs is triggered by hormones), and the multiple eggs are collected by surgery called laparoscopy. Next the eggs are fertilized in a test tube with sperm from a donor male; the resulting embryos can be frozen for storage (see picture above – From www.westholmewagyu.com.au), or immediately implanted into a closely related but non-endangered species for full-term growth, birth, and later foster rearing by the surrogate mother.
Fostering – There are some animals which can breed successfully in captivity, but are unable to raise their own young. In these situations, the young can be raised by another similar species. This is most commonly used in birds. An example being the Asiatic jungle fowl whose chicks are incubated and reared by domestic chickens! Also, the eggs of whooping cranes can be placed in nests of wild, closely-related sandhill cranes which then raise them.
The Pros and Cons of Captive Breeding
Pros
90% of all mammals and 74% of all birds which have been added to U.S. zoo collections since 1985 have been born in captivity. (This is a pro because it means zoos are supplied without having to capture wild animals). There are some species which are extinct in the wild but have been saved in zoos: such as Przewalski's horse and the Arabian Oryx. A number of wild populations of species were born in captivity and now live free: Bald Eagle, Gold Lion Tamrin Andean condors, and red wolves which is a great ethical pro as these animals are no-longer forced to live solely in human captivity. An environmental pro is that successful captive breeding programs can promote the creation of wildlife refuges, such as in southern Arizona with a bobwhite quail which allowed its successful reintroduction. A Social pro is how public awareness and concern can be raised by such efforts if they are well publicized.
Cons
However an ethical con is that captive breeding programmes focus on a few endangered species, the ones which most appeal to us as worth saving. Genetic diversity of some species may have become too low to allow adequate sized gene pool for successful reintroduction leading to inbreeding and the degradation of a species. Unfortunately quite a large economic con is that it is highly expensive and diverts resources from much more cost-effective ecosystem and habitat conservation projects which is in turn an environmental con. It implies to the public that the battle against extinction is going well which is a lie, whereas many species are still heavily under threat, and crucial habitat is still being destroyed, e.g. the Amazon Rainforest, an environmental con as support then lessens. If the habitat no longer exists, or is not expected to exist in 200 years time, where will the animals go? And some people believe that it is better to let the species become extinct than keep them under false conditions (Playing God). Socially it can produce problems such as the reintroductions of wolves which have since attacked farmers sheep and other livestock.
How zoos Ensure Genetic Diversity
The problems with breeding from and maintaining a small captive population is the small gene pool, which if bred from randomly is likely to lead to inbreeding and genetic degradation. Small gene pools lead to a higher likelihood of recessive alleles being expressed, causing problems for the animals either with direct physical/mental consequences or by increasing their susceptibility to diseases, e.g. a population where every creature is vulnerable to a specific disease can be wiped out easily. So to overcome these problems zoos keep extensive records of each creature’s lineage so it is possible for them to tell if the potential breeding pairs will be inbreeding. The animals are selected from the worldwide database according to their lineage and shipped to other zoos to create the best potential matching. This is only done however if there is a place in another zoo around the world for the offspring of the pairing, this avoids overcrowding.
Possible Future developments:
It is hard to speculate on the future of animals which are in danger of having no future at all, however the techniques currently used to store eggs sperm and embryos could be maintained for a long time, meaning that while there may currently be no-where for some species to go, in the future if more reserves are constructed that would not currently be possible, it would be possible to bring back a species which had in the mean time become extinct. The embryos could be surrogated by the closest existing species to the extinct animal giving it a good chance at re-establishing its presence in the world. This would allow future generations to enjoy the beauty of some endangered animals, and allow the animals to have a second chance free from the destruction caused by humanity.
Analysis
To write this report I used a number of recourses the majority of the information was from the Paignton zoo official website itself. It’s not fully complete because the website concentrated on the zoos activates and a little information about other zoos. The leaflets from the zoo were also quiet useful, providing the current projects being carried out by the modern zoos. I feel this information is reliable, because it comes from a reputable source, and while some of their campaigning may by based upon opinions, the details about what they are currently doing is factual.
The speaker from Paignton while obviously bias, provided an insight into what as a zoo Paignton is doing for conservation, along with giving details about the processes involved in captive breeding.
Also I have used the book called ‘breeding endangered species in captivity’ written by R.D Martin which was useful in providing an understanding of breeding but I didn’t used it much in the report as it’s edited in 1975.and it needed dated. Another book I have used is ‘the stationary Ark’ written by Gerald Durrell,which showed more about breeding.
Other websites though provided some information not much was taken from them other than some picture.
Bibliography
Websites
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Books
- The Stationary Ark –Gerald Durrell – ISBN: 0002167425
Publisher: HARPERCOLLINS
Publication Date: 1976
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Breeding endangered species in captivity – report on conference on the breeding of endangered species.
Edited by- R.D Martin in 1975
- The speaker at a Paignton Zoo educational lecture - Julian Chapman
- A leaflet provided by Paignton about Conservation (Titled Conservation at Paignton + Conservation in Nigeria )
